Expo and delay in controls in manual?

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hi folks

i’ve setup up a falcon flying wing with arduplane. i set it all up last week so i’m assuming it has the latest version of the firmware?

anyway, i’m running ezuhf for control and i have elevon mixing in the tranny setup. it flies fine in manual and fbwa, fbwb, circle, rtl etc.

however, when in manual, the inputs i make on the sticks seem a little delayed before they come through on the elevons. maybe fractions of a second but enough for me to notice. the servos also move a little bit jittery?

would it be that i’m using digital metal servos? or could it be something else like maybe expo in the apm? does apm even have expo paramaters?

any thoughts much appreciated

d

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Did you ever figure this out. I’m trying to get my RVJet in the air. Been trying for a year now it seems. I don’t trust it until I get the jitter and delay fixed.

Pixhawk
Turnigy 9x
3dr pwm/ppm converter.

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I did a direct measurement of servo lag with APM:Plane in manual mode here:
github.com/diydrones/ardupilot/issues/1816
It shows the lag is what we expect - between 20ms and 40ms.
It is quite common for servo lag to happen in some systems for other reasons. The most common is insufficient power to the servo rail or bad grounding of the servos.
Cheers, Tridge

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Hello Tridge,
Thanks for replying.
I can understand the delay, it needs to be processed.
Have you seen anything like this?

jaxlees.com/wp-content/uploads/2 … ng-out.png

When I raise throttle, radio quits for a bit. I’m using the PWM/PPM encoder board and a turnigy reciever. After some stutters it’s all good again.

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[quote=“allioupe”]Have you seen anything like this?

jaxlees.com/wp-content/uploads/2 … ng-out.png

When I raise throttle, radio quits for a bit. I’m using the PWM/PPM encoder board and a turnigy reciever. After some stutters it’s all good again.[/quote]
Generally it is better posting a tlog as it has a lot more details. Screen captures of graphs are quite difficult to analyze.
Even so, it sounds like you may have an issue with your encoder. If you want to properly diagnose it you would need a logic analyser and oscilloscope, but it is probably easier just to get a receiver that has PPM-SUM, SBUS or DSM outputs.
Sometimes people can resolve issues like this by replacing a BEC or by improving their ground connection, but the list of possible causes is quite long, and a single wire connection will end up being more reliable and have better failsafe characteristics.
Cheers, Tridge

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I received my Taranis today. I switched out the Turnigy receiver and the 3dr converter for the L9R. I connected the SBUS out on the receiver to the RC In on the Pixhawk. Results… no lag at all. in all modes. It felt like it was a direct connection to the servos. No drop out either. I wonder if the converter was being overloaded and was resetting or something.

Now this is out of the way. I’ll be tossing her in the air tomorrow.